Cylinder-lock.



0. A. MULLER.

CYLINDER LOCK.

APPLICATION FILED AUG. 9, 1912.

1,1 14,709. Patented Oct. 20, 1914.

UNITED STATES PATENT OFFICE.

CARL AUGUST MuLLER, or WI'IZENHAUSEN, GERMANY.

CYLINDER- OCK.

1,114,709 Specification of Letters Patent. Patgntgd Oct, 20 1914,

Application filed August 9, 1912. Serial No. 714,236.

. To all whom it may concern Be it known that I, CARL AUGUST MI'iL- LER, a subject of the German Emperor, residing at WVitzenhausen, Germany, have invented certain new and useful Improvements in (lylindereLocks, of which the following is a specification.

The pin tumblers of safety looks with rotating cylindrical plug hitherto used, in which .the said tumblers controlled by springs engage from the casing with the rotating body and are adjusted or set bythe key by means of drivers, were formerly made either in such a way that after the destruction of the parts by means of which they were set and which were of the same diameter, they could enter their guide holes as their travel was unlimited, so that the security of the lock was destroyed, or they were partly provided with a limitation of the travel which however was not suitable for insuring the safety of the lock. As is well known, attempts are made to force open the locks by boring the locking parts.

If the tumblers lock under the action of intermediate parts, it will always be found that they will be destroyed by boring. Tumblers provided with ,a I strengthened head or the like, the travel of which is thus partly limited, also enable the lock to.be easily opened by simply boring the part in question. This disadvantage is obviated by the present invention by the tumblers being made of such shape that both after the (le struction of the parts adjusting or setting the same, as well as of their. locking parts proper, they still continue to lock the lock independently. Only with pin tumblers formed throughout the whole of their length for independent locking, is it possible to obtain a lock giving a real security, as they oppose the greatest possible obstacle to any attempts at destruction. Such tumblers of course increase considerably the safety of the lock.

A construction of a safety lock provided with tumblers of such construction is shown in Figures 1 and 2 of the accompanying drawing, while Figs. 3 to 9 show modified constructions.

The rotating body a is locked relatively to the casing 12 by the spring controlled followers 0 in the well-known manner, the followers being arranged for operation by means of drivers d operated by the key, one or more locking bodies or followers and drivers being provided as desired. In order to prevent the followers from passing directlylinto their guide conduit after the destruction of thedrivers d opposite the same, whereby the locking would be destroyed, theyare constructed according to this invention so that they have throughout the whole of their length alimited travel. This is done according to Figs. 1 and 2 by the followers being given throughout the whole of their length, a greater diameter than that of the drivers and their guide conduit. If it is attempted to force the lock open by boring away the locking portion between the body a and the casing b, the tumbler will at once advance and look again, which is not the case for instance in tumblers provided with a head.

The increase of diameter relatively to that of the opposite parts, extends the whole length and the Whole circumference of the tumblers 0, but it could also extend only to a portion of the circumference, the widened portion being given the shape of flanges e (Fig. 3). It can also be obtained by separate auxiliary bodies, for instance balls f (Figs. 4-8), mounted in separate recesses of the followers, the mounting on the two opposite sides being if desired alternate as shown in Fig. 5. The mounting can also be in a helical line, as shown in Fig. 6. The halls can also pass through the followers, for instance be arranged in perforations of any desired arrangement (Figs. 7 and 8). More particularly, when balls as har as glass are used, these followers ofl'er considerable resistance to boring, because on one ball and the locking point of the tumbler being bored away, another ball at once takes over the limiting of the'travel of the tumbler by falling after it. The followers themselves can then be constituted by balls, namely of a greater diameter than that of the opposite guide holes (Fig. 9). The halls could be connected together for instance by a pin passing through them. The construction can vary, and thesame applies to the cross section of the tumblers. Thus for instance the widening of the tumblers can be obtained by insertion of metal pieces as hard as glass (for instance ledges cir. Fig. 3).

What I claim as my invention and desire to secure by Letters Patent is 1. In a tumbler lock, a cylindrical casing, a cylinder rotatablewithin said casing, in-

rows of balls in said casing of larger dif ameter than the intermediate parts, and

shoulders in the recesses of the cylinders adapted to be engaged by said rows of balls.

In testimony whereof I have signed my 15 name to this specification in the presence of tWo subscribing Witnesses.

CARL AUGUST MnLLEn.

Witnesses UDO HAASE, ENGELHARDT GERSTENBERG. 

